1. Field of the Invention
The present invention relates to a pump; and more particularly relates to a diaphragm pump, e.g., for use in a soft drink dispenser.
2. Brief Description of Related Art
Pump are known in the art that use compressed gas to drive a reciprocating piston which in turn, creates a variable volume displacement and transfers pressure to the fluid. See U.S. Pat. No. 5,664,940, which is hereby incorporated by reference in its entirety. In operation, the device moves the fluid under pressure from a storage container called the Bag-In-Box (BIB) to the soft drink dispenser.
In addition, these types of pumps typically may have a vacuum actuated gas shutoff valve incorporated into the design. The ASO (automatic shutoff) valve stops the flow of gas to the pump when the vacuum reaches a specific value.
By way of example, such known pumps may include, or take the form of, an air-operated pump, which is generally a low cost work horse pump used for transferring any type of liquid, e.g., including fluid from a bag to a beverage dispenser, as well sludge. The pump may include inlet and outlet valves that take the form of flap or ball valves. The pump also includes two circular chambers each split by a large elastomeric diaphragm. The two diaphragm centers may be mechanically coupled together with a shaft. An interlocked valve admits air pressure to one side of one of the chambers and exhaust the air from the opposite side of the other chamber. This causes both diaphragms to move. One diaphragm pushing fluid out through a non-return valve. The other diaphragm drawing fluid in through another non-return valve. On completion of a full stroke the valve reverses the air supply and exhaust directions causing the diaphragms to move back. The diaphragm which was pushing fluid out of the pump now sucks fluid and the diaphragm admitting fluid now pushes fluid out. The system is therefore double acting. See also U.S. Pat. Nos. 4,94,574; 4,500,264 and 4,555,222, which are all incorporated by reference in their entirety.
Each pump is mounted to a specialized mounting bracket specified by our customer. There are three distinct mounting configurations: wall mount, slide track mounting and UMB (universal modular board).
Since the ASO in most BIB pumps is activated at a predetermined value, there is typically no means of adjustment. Occasionally, the shutoff value requires fine tuning to compensate for altitude considerations however most pumps do not accommodate this feature.
Currently, when the ASO is activated there is no way for the end user to identify the state of the syrup system. If the soft drink dispenser is not dispensing syrup, some users are not able to troubleshoot and identify the need to change the syrup supply. Consequently, a service call is initiated at a cost to the syrup supplier.
The current pump is mounted with other pumps such that they share a common gas supply through a distribution manifold. This manifold is assembled at the factory and utilizes components that are expensive. In addition, when removing the pump from service, a separate activity is required to disconnect the gas source from the pump.
In view of this, there is a need in the marketplace for such a pump to be able to be adjusted by the end user, and for the end user to identify the state of the syrup system.